Epidendrum alsum Ridl.

 

Epidendrum alsum is a species of flowering plant in the family Orchidaceae, native to south-east Venezuela and Guyana. It was first described by Henry Nicholas Ridley in 1886.

Epidendrum alsum - Wikipedia

Epidendrum alsum is one of the less colorful orchid flowers here on top of Roraima.

According to Flora of the Venezuelan Guyana Vol 4:
“Both Epidendrum ulei and alsum are two of several members of the Epidendrum dendroobioides-durum complex, a group of mainly terrestrial taxa usually restricted to sandstone-derived or boggy substrates”.

A couple of characters separating ulei and alsum from each other: ulei is potentially much taller – 50- 150 cm tall vs 25-40 cm for alsum yellow flowers of alsum vs greenish yellow or green for ulei.

Native range is the Guyana Shield.

Epidendrum alsum | Morten Ross

Description: Perennial herb with stem-like stems that are erect, leafy in the upper part, 20–25(–35) cm tall. Leaves sessile to embracing, alternate, on stem double-rowed, lanceolate to ovate, 20–35 mm long and 15–20 mm wide, margins curved downwards to undercoiled, apex with a set tip, leathery, distinctly keeled. Inflorescence terminal, panicle, distinctly longer than leaves, composed of downward-drooping 5–8-flowered racemes, their spindles "zigzag" angular; bracts 4–5 mm long; flowers are small, often desolate, outer petals elliptic, 6–7 mm long, yellowish-green, inner 4.5–5.5 mm long, narrower than the outer, lip shuttle-shaped, about 6 mm long. The fruit is a capsule.

Threat and protection: It is subject to the protection of the international convention on trade in endangered species CITES.

EPIDENDRUM ALSUM Ridl. – Postromice | BOTANY.cz